Improvement in steam-boilers



C.' SHAW'. Steam-Boiler.

No. 199,866-, Patented 1m29, 1878.

NA PETERS. PHOTO-UTHDGRAPHER, WASHINGTON. D. c.

UNITED STATES PATENT OEEIcE.

CHARLES SHAW, OF BRIDGEPORT, CONNECTICUT.

IMPROVEMENT IN STEAM-BOILERS.

Specification forming part of Letters Patent No. 199,866, dated January 29, 1878; application filed December 15, 1877.

To all lwhom t may concern i Be it known that I, CHARLES SHAW, of Bridgeport, in the county of Fairfield and State of Connecticut, have invented an Improvement in Steam-Boilers; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawing, forming part of this speciiication.

My invention relates to tubular steam-boilers, principally of the locomotive type, and has for its object such an improved construction of tubular boilers as will increase their efficiency in use and their durability.

Figure l in the accompanying drawing` represents a central vertical section of a boiler constructed in vaccordance with my invention. Fig. 2 is a partial end view and partial section of the same. Fig. 3 is a section made on the line x .fr in Fig. 1.

A, A', A", and A represent the outer shell of a boiler constructed in four courses, represented respectively by the said letters of reference.

A is a vertical cylindrical course, joined to the lirst horizontal course A by the elbow or miter joint b. A' is a horizontal cylindrical course, united to the conical course A, which extends entirely around the boiler, and is in turn joined to the horizontal cylindrical course A". The course A' is of smaller diameter than the course A.

B B' isthe Jrire-box, the part vB of which is cylindrical, and the part B of which is semicylindrical, the flat side of said part Bl being at C, and forming a tube-plate. The end of the boiler C forms the other tube-plate.

The`tubes D are inserted in the said tubeplates in the u'sual manner.

The front side'of the lire-box B B is substantially concentric with the front side of the vertical course A through its entire height, and the back side of the part B of the furnace is substantially concentric with the back side of the said vertical course A.`

This construction secures a cylindrical waterleg, E, entirely surrounding the fire-box, and lessens the unequal expansion of plates, which injures the platesof boilers constructed according to other methods, and having many angles.

The smaller diameter of the course A secures the application of the heated gases of combustion, after their heat has been partially extracted, to a smaller body of Water; andv the connection of the said course with the conical course A" secures a better circulationA between the back end of the boiler and the water-leg E, which aids in maintaining a more uniform temperature throughout the boiler than has hitherto been attained.

By this construction I am to a greater eX- tent enabled to avoid right angles, and to use and to secure the benefits of cylindrical construction throughout nearly all parts of the boiler, thereby obtaining a more durable tubular boiler than has hitherto been manufactured.

To secure a more perfect combustion of gases above the fuel on the grate F, I place on the front -of the vertical course A, above the fire-box doorAI, an air-box, G, provided with a valve, (preferably a register-valve,) and I connect the said air-box with the interior of the nre-box by means oi' tubes j, which pass through the water-leg E.

By this means I am able to supply air to the unconsumed gases above the fuel in right proportion to secure perfect combustion, and, as the tubes j are surrounded with heated water, the said tubes impart heat to the air, and I thus measurably secure thc advantages of a hot draft.

I claiml. In a tubular boiler, the combination of the vertical course A, having its entire upper edge beveled or mitered, and the horizontal course A', having its entire front edge correspondingly mitered or beveled and joined thereto, so that the top surface of the boiler fully overlaps the vertical course, substantially as described. j

2. The combination, in a tubular boiler, of the cylindrical courses A Af, and the truncated conical courseA", connecting said cylindrical courses, and forming an oblique wall entirely around the boiler, substantially asl set forth.

8. ln a tubular boiler of the locomotive type, the lire-box composed of the lower cylindrical part B and the upper semi-cylindrical part B', the flat side of which forms a tube-plate, substantially as and for the purpose set forth.

CHARLES SHAW. Witnesses RUDOLPH KORT, JosErH RIGNEY. 

